High colony stimulating activity in a patient with disseminated carcinoma and neutrophil leucocytosis

The case of a man with widespread bronchogenic carcinoma associated with pronounced neutrophil leucocytosis is presented. There was no evidence of infection or metastatic bone marrow infiltration. Increased levels of colony stimulating activity were shown in the patient's serum using three methods. Findings in this patient suggest that the leukaemoid blood picture was related to inappropriate tumour associated production of colony stimulating factors.